Lambs are young, domestic sheep. That means lamb is the meat of a young sheep. However, the age of the lamb will differentiate it from hogget, and furthermore, mutton. A sheep under one year of age is considered a lamb, but meat from lambs under one year of age is not always lamb meat. When a lamb is still under two years of age, they are not yet a full-grown adult, so the meat of the animal is referred to as hogget. This term is rare in the United States, and is more common in Commonwealth countries. Finally, when a lamb has crossed their 2-year birthday, they enter adulthood, making their meat mutton.
Lamb – a baby sheep, under one year of age. When the meat is processed early on, between 4 and 5 months, it is a tender lamb meat that is lighter in color and retains a true lamb meat flavor. When lambs are processed after that time, their meat takes on different characteristics.
Hogget – A juvenile lamb that is older than 5 months, but younger than 2 years old will produce a darker, gamier flavor of meat commonly referred to as hogget. In the U.S., this meat is simple called mutton or lamb.
Mutton – The meat of an adult sheep, age 2 years and older, is called mutton. It is a darker meat, less tender than lamb, and retains a gamier flavor. In South Asia, mutton is also used to describe goat’s meat.